Comparison of Two Doses of Mannitol on Brain Relaxation During Supratentorial Craniotomy
Status:
Completed
Trial end date:
2011-05-01
Target enrollment:
Participant gender:
Summary
Neuroanesthesia for supratentorial surgery involves a thorough understanding of the
physiopathology of intracranial pressure, cerebral homeostasis and regulation of cerebral
perfusion pressure as well as the effects of anesthesia and surgery on these elements.
The main objective of anesthesia during neurosurgery is to preserve the integrity of the
brain by maintaining cerebral homeostasis, and assuring cerebral protection using
normovolemia, normotension, normoglycemia, moderate hyperoxia and hypocapnia and
hyperosmolality with the administration of mannitol.
During surgery, the use of surgical retractors must be limited to avoid possible ischemia of
the brain tissue. Surgical retractors can be replaced by chemical retractors. The concept of
chemical retraction involves a reduction of cerebral blood flow, maintaining cerebral
perfusion pressure, moderate hyperventilation, drainage of cerebrospinal fluid and
osmotherapy.
Mannitol, an osmotic agent, has been widely used to reduce the volume of the brain, the
intracranial pressure and to facilitate the surgical approach in reducing the risk of
cortical lesions during the opening of the skull.
Mannitol 20% is usually given intravenously in bolus doses of 0.5-1g/kg over 30 minutes.
However, over the last few years, the concept of a dose-response relationship has emerged.
Some recent studies tend to demonstrate that higher doses of mannitol could reduce
intracranial pressure significantly without any important side effects.
The main objective of the present study is to compare two doses of mannitol (0.7 and 1.4
g/kg) on brain relaxation during supratentorial craniotomies.